Ear-tip for stethoscope type headset



' 1957 A. L. Di MATTIA EAR-TIP FOR STETHOSCOPE TYPE HEADSET Filed Aug. 11, 1955 /lrl, v/IIIIIIIIIIIII/ I m s R C mm 2 M W .6 A a l mm 4 2 y. n w a T1 a] 3 H H w j. 4 5 5 hm United States Patent EAR-TIP FOR STETHOSCOPE TYPE HEADSET Alfred L. Di Mattie, Fairfield, Conn., assignor to Dictaphone Corporation, Bridgeport, Conm, a corporation of New York Application August 11, 1955, Serial No. 527,807 Claims. (Cl. 181-213) This invention relates to improved car tips, and to a method of fabricating them, for stethoscope type headsets.

An object of this invention is to provide a stethoscope headset which can be worn comfortably by a user for long periods of time.

A further object is to provide such a headset which fits a users ear better and makes hearing easier than headsets in the past.

A more specific object is to provide an improved eartip for such a headset which is very inexpensive but yet of the highest quality.

Stethoscope type headsets are widely used in business ofiices in conjunction with dictation transcribing machines. This type of headset derives its popularity because of its many advantages; for example, it fits snugly into the ear of a user thus providing good sound coupling from the headset and excluding outside sounds, it is light in weight, and it is easily put on or taken off even when the users hair covers her ears. 7

One difiiculty in the past with this type headset was that the ear tips provided were made of a relatively hard material, such as Bakelite or solid rubber. When such a headset was used, its tips entered the ear canals of the user and deformed these canals to fit the shape of the tips. Though the amount of deformation of these canals was generally slight and not noticeable for short periods of time, it gradually caused more and more discomfort as time went on until finally wearing the headset was painful.

A second difficulty in the past was that the ear tips for this type of headset were rigidly fixed to the ends of the headset arm. When these tips were in place in the users ears, any pendulous swinging of the headset caused a painful twisting or pulling of the skin and tissue lining the ear canals. To prevent this, either the headset was allowed to swing with its tips fitted only lightly in the ear canals, and as a result the most effective sound coupling to the car was not obtained, or else the headset was held from swinging in spite of all the attendant inconvenience of doing this.

The present invention seeks to provide a stethoscope headset free of the above described difficulties. In accordance with one aspect of the present invention, such a headset is fitted with ear tips having almost balloon-like flexibility so that they can easily and comfortably and with very light pressure conform to the ear canals of a user. Since these ear tips are so very flexible, they can conform to practically all sizes of ear canals so that one standard size of tip can accommodate most users.

In accordance with a second aspect of the invention each ear tip for the headset is made free to rotate easily at the end of its respective arm. Thus though the tip is securely seated in the users ear, the headset can stillbe permitted to swing without turning the ear-tip and thus causing discomfort. The swivel joint between tip and arm, though it is very simple, is very efficient acoustically so that so far as the sound waves from the headset are concerned, the tip is an integral part of the arm.

The fabrication of these ear tips is carried out in ac-. cordance with another aspect of the invention by a method which permits them to be made cheaply and with perfect- 1y formed shape. As a result they are not only inexpensive but have a very smooth surface with no bothersome irregularities which would otherwise later and at ad ditional expense have to be removed. The ear tips according to the invention are fabricated separate from the headset but are made so that they can easily snap on or off the ends of the headset arms. Since the tips them selves are so inexpensive and since they can so easily be unsnapped from a headset, a single headset body can serve many users with each user having a set of tips for her own personal use.

A better understanding of the invention together with a fuller appreciation of its many advantages will best be gained from the following description given in connection with the accompanying drawings in which:

Figure 1 is a perspective view of a user wearing a stethoscope headset;

Figure 2 is a side section View, greatly enlarged, of one ear tip and a short portion of an arm of the stethoscope shown in Figure 1;

Figure 3 is a side section view of the ear tip shown in Figure 2, but shown here unfolded and in the form in which it is moulded;

Figure 4 shows in side view the details of the end of a headset arm and of the ear-tip ferrule which is adapted to fit upon the end of this arm; and

Figure 5 shows a cross section taken as indicated by lines 5-5 in Figure 2.

As seen in Figure 1, a stethoscope headset 10 is clamped upon the head of a user, the tips 12 of the headset being inserted in the users ears. At the base of the headset, where its arms 14 and 16 are pivotally joined together, is a miniature sound reproducing unit 18 of any suitable kind. Sound generated by this unit is directed along hollow passages within arms 14 and 16 to the ears of the user. Unit 18 is connected by means of a pair of wires 20 to a reproducing unit (not shown) such as, for example, a dictation transcribing machine. Ear tips 12, which are identical, are supported in freely rotating relation upon the ends of their respective arms 14 and 16. Headset 10 may therefore without causing discomfort swing back and forth beneath the chin of the user.

Figure 2 shows in greatly enlarged cross section the end portion of the arm 14 together with its tip 12, the end of arm 16 and its tip being identical to these. Tip 12 consists of a single piece 22 of thin walled rubber folded back upon itself and cylindrically around the ferrule 24.. Piece 22 is bonded along a portion of its inside surface to the ferrule as will be explained.

Ferrule 24 fits snugly around the end of arm 14, being held thereon by means of the dimples 26 in it which engage the groove 28 in the arm 14. This manner of fitting the ferrule to the end of the arm is such that they are in freely rotatable relation to each other, and moreover, can easily be separated when and as often as desired. Both ferrule 24 and arm 14 are metal and therefore the rotational friction between them is less than if one were made of rubber, for example.

To permit the dimples 26 to slip out of groove 28 so that the tip 12 can be removed from the arm, ferrule 24 is cut in four places partly along its length. The slots 30 formed by these cuts are clearly shown in Figures 4 and 5, along with their positions relative to dimples 26. The portions of the ferrule which are indented by the dimples 26 can thus act as leaf springs normally urging the dimples into groove 28 but permitting them to move out when sufilcient pull is exerted on the tip.

The single piece 22 of the ear tip is fitted in one piece around the ferrule 24. Piece 22 can be made from any suitable material which is sufficiently flexible, such as rubber. The shape in which it is originally moulded is shown in Figure 3. Here, piece 22, including the narrow neck portion 32, and the bulb like part 34, is moulded around an appropriately shaped and highly polished removable mandrel 36 shown in dotted outline. This mandrel is made in one piece and when removed from within piece 22 leaves a very smooth and seamless surface. The outer mould (not shown) for forming piece 22 can be made in two or more mating parts since any seam or seams which may be left by this outer mould on the piece 22 will be covered over when the part 34 is folded back upon itself and placed upon the ferrule as shown in Figure 2.

As seen in Figure 3, the wall at the right end of piece 22 is thicker than at its other parts. This not only strengthens the piece 22 but helps it stay folded into an ear tip. The thickened part of this wall at its left end has a shoulder 38 which is adapted to mate with the left end 40 of piece 22 when, as shown in Figure 2, this piece is folded back upon itself. Thus once folded back, it will tend to stay folded unless and until shoulder 38 is lifted over end 40.

As seen in Figure 2, the annular space 42 between the folds of piece 22 adds to the great flexibility of tip 12 and helps it conform easily and with substantially uniform pressure at every point to the ear canal of the user. Thus there will be almost no tendency for this ear tip to cause discomfort even though it is firmly seated against the users ear. Moreover, even a light inward force on the tip will produce a perfect or a nearly perfect fit of tip to ear thus further reducing any possibility of discomfort. The pressure of the air within space 42 is kept equal to the outside air pressure by the openings provided by slots 30 in ferrule 24 and the slight separation between shoulder 38 and end 40 of the piece 22.

Referring to Figure 4, the right end of arm 14 is beveled at 44. This bevel 44 mates with the inner bevel 46 at the right end of ferrule 24. In this way, the rotating joint between tip and arm is made self-aligning and can be kept tightly sealed to the sound waves passing through arm 14. The distance between bevel 44 and groove 28 on arm 14 and the distance between bevel 46 and dimples 26 on ferrule 24 are such that bevel 44- is held snugly against bevel 46 when the headset is being worn.

As indicated in Figure 4, the right portion of ferrule 24 is knurled lightly so that the rubber piece 22 can be bonded tightly around it and will not slip off.

The above description is intended in illustration and not in limitation of the invention. Various changes in the structure described may occur to those skilled in the art and these can be made without departing from the spirit or scope of the invention as set forth.

I claim:

1. A stethoscope type headset comprising two arms each having an opening along its length, and an ear tip for each arm, said ear tip being adapted to fit snugly into the ear of a user, to fit around the end of an arm and to be rotatably supported thereon, said ear tip including a soft flexible member surrounding the opening at the end of said arm and enclosing a doughnut-like air space within itself whereby said ear tip is able to conform easily to the ear canal of the user.

2. An ear tip for a stethoscope type headset comprising a cylindrical short length tube open at both ends, and adapted to fit upon the end of a stethoscope arm, being retained thereon in rotatable relation thereto, and a soft flexible member surrounding an end of said tube and being adapted to fit into a users ear, said ear tip having an annular surface at one end which is adapted to abut a mating surface carried by the arm and to provide a ro tatable joint therewith which is sealed to sound waves when the headset is worn.

3. The combination of elements as in claim 2 wherein said annular surface is a surface carried by said tube and lying at an angle relative to the axis of said tube.

4. The combination of elements as in claim 3 in which said annular surface is on the inside of said tube at one end thereof and is adapted to mate with a beveled surface on the end of the stethoscope arm.

5. The combination of elements as in claim 4 in which said soft flexible member is adapted to be snugly seated in the ear of a user and said ear tip can easily rotate relative to the stethoscope arm whereby the stethoscope can swing without causing painful twisting of said ear tip.

6. An ear tip having balloon-like flexibility and adapted to fit rotatably upon the arm of a headset of the character described, said ear tip comprising a cylindrical ferrule, and a one-piece thin walled tube-like flexible member folded back upon itself and fitted around an end of said ferrule, the folds of said one-piece flexible member at one end enclosing a doughnut-like air space.

7. The combination of elements as in claim 6 in which said ferrule is slotted and dimpled at one end and is adapted to snap on and off the end of either one of the headset arms.

8. The combination of elements as in claim 6 in which said ferrule has a beveled inner surface at one end which is adapted to mate with a complementary beveled surface on the end of a headset arm.

9. An ear tip arrangement having super flexibility, said ear tip comprising a thin-walled relatively stifi tube, and a one-piece annular member of flexible material fixed along its inner surface to the outside of said tube, the outer surface of said member being gradually curved from a small diameter at a first end to a large diameter near the other end and then rapidly curved to a small diameter at said other end to give it a bulbous shape, the inner and outer surfaces of said member adjacent said other end enclosing an annular volume into which said member can be compressed to give it super flexibility in fitting the ear of a user and in cushioning said tube from the users ear.

10. A method of forming a smooth surface ear tip having balloon-like flexibility comprising the steps of taking a generally round inner mandrel which is smooth and seamless around its circumference and which has a first generally cylindrical portion of a first diameter along its length, a second generally cylindrical portion adjacent the first and somewhat shorter and thinner, and a third portion adjacent the second and having a bulb-like shape with a large diameter adjacent said second portion curving to a smaller diameter, moulding a thin-walled rubberlike tube around said mandrel, inserting a relatively stiff tubular ferrule into the part of said rubber-like tube which was formed around the first portion of said mandrel, and folding the remaining part of said rubber-like tube back over itself to enclose a doughnut-like volume within itself at one end.

References Cited in the file of this patent UNITED STATES PATENTS 1,045,812 Campbell Dec. 3, 1912 1,893,474 Lieber Jan. 3, 1933 2,220,208 Cannon Nov. 5, 1940 2,288,966 Blanchet July 7, 1942 2,605,195 Boughton July 29, 1952 2,650,633 Eger Sept. 1, 1953 

